Conventionally, for connecting, for example, a general computer system with an external printer or the like, latch apparatus have been widely used in connecting a connector which is a securing member provided for an input-output printer port on the computer side and a connector which is a securing member on the cable side. The latter connector is standardized in line with the former connector and connected to the external printer. The latch apparatus is utilized for fastening, or latching, the connector on the computer side and the connector on the cable side.
Such conventional latch apparatus include: an elastic body (spring); a freely turnable support member to support the elastic body; and a holding member (latching plate) to which a connector on the cable side is attached and which engages the elastic body, wherein the elastic body turns about its support portions which act as fulcrums, and the elastic body engages the holding member. The connector on the computer side and the connector on the cable side join so as to fasten the cable from the external printer to the printer port, so that the external printer or the like may be connected to the computer device.
The operation of the above mentioned conventional latch apparatus is described below.
FIGS. 7a, 7b, respectively, show a front view and a side view of the latch spring which is an elastic body in a conventional latch apparatus. FIG. 8a, FIG. 8b, and FIG. 8c, respectively, illustrate a top view, a front view and a side view of the engaging operation of the latch spring.
As shown in these prior art figures, a conventional latch spring 20 which is an elastic body is engaged by fitting spring legs 8 which are holding portions into axial holes 7 of a spring leg holder 2 which is a support member of the latch spring, and the spring leg holder 2 is fastened to a mounting base 3 by a screw 4. Alternatively, a spring holder 5 which is a holding member is fastened to a connector 10 on the cable side by a screw 9.
A second connector 10 is engaged with a first connector 11 of the mounting base 3 on the computer side, and at this moment, the conventional latch spring 20 is turned in the direction of the arrow Y50 around the spring leg holder 2, and the conventional latch spring 20 contacts and engages a holder groove 6 of the spring holder 5. Consequently, the first and second connector 11, 10 are engaged and connected. That is, the second connector 10 is prevented from slipping off the first connector 11 by holding the spring holder 5 by using spatially two-dimensional spring shoulders 21 in the conventional latch spring 20.
However, in the above mentioned conventional latch equipment, as shown in FIG. 7 and FIG. 8, the spring shoulder 21 in the conventional latch spring 20 to be engaged with the spring holder 5 has a two-dimensional shape, and therefore, in the case where a cable connected to the computer device is caught, the cable is pulled, and pressure is added to the second connector 10 on the cable side in the direction of being pulled out of the first connector 11 (direction shown by an arrow Y51). Accordingly, the shape of the conventional latch spring 20 may easily be deformed and the latching force is lost, posing the problem that the cable often slips off the computer device.
To solve this problem, first connector 11 on the computer side and the second connector 10 on the cable side are often fastened not by engagement of the conventional latch spring 20, but by a screw. However, this solution poses another problem. The operating performance for connection and removal of an external device like a printer worsens and the simple operation of removal and insertion of a cable becomes more difficult.
The present invention solves the above mentioned conventional problems, and provides a latch apparatus which can securely connect and fasten the connector on the spring holder side to the connector on the spring leg holder side, thereby preventing the connectors from slipping off and separating while offering a simple configuration as compared to a conventional latch spring.